Ruby is Rinko and Akari's Jewelpet partner and the secondary heroine of the series. She is a White Japanese Hare who symbolizes courage and wears a pink and red cherry blossom on her head. She also wears a necklace shaped like a pair of red cherries. Ruby is the only Jewelpet who has the "Acrylic Class" ranking due to her magic, which can cause bad luck and explosions when she casts it to someone but sometimes her magic has 1% chance of success. Due to her bad behavior, in-attendance and goofing off, she was punished by the Four Witches of Jewel Land, turning her into a Jewel Charm and sent her to Earth to find all of her lost friends. Her Jewel Charm form fell into Rinko's drinking glass on that night and then being awakened by Rinko's Magic using the Jewel Pocketbook the next day. Her personality is a bit joyful, brash, happy and sometimes a BIG troublemaker, which makes her partner Rinko have a hard time handling her. Despite all of this, she and Rinko were appointed to find the other missing Jewelpets on Earth and handling every problem her partner encounters.

It's revealed that Ruby is the ancestor of the savior of both the Human World and Jewel Land along with Rinko's Ancestor. She has a big crush on Tooru the American shorthair cat and sometimes called "Romper Lady" by him. in Episode 51, She earned her "Superior Crystal Class" rank in magic and summoned Opal the unicorn in the final battle against Dark Dian. But then she found out that it was temporary as she is now back as an Acrylic Class Jewelpet. In Jewelpet Tinkle, Ruby is a new Student in the Magic Academy. Her first test to get in is to find a Human Partner on Earth, which happens after she met Akari. After that, she got accepted in the academy along with Akari. Her birthday is on July 29th and her name is based on the Gemstone Ruby.

Ruby can also use the Jewel Pocketbook to awaken Jewelpets from their jewel forms. She can also wield a miniaturized version of the Jewel Stick for her magic or with Garnet and Sapphy, to summon other Jewelpets from Jewel Land. She has also the ability to summon Opal. In Season 2, Ruby is the only Jewelpet who can use the Jewel Pot while she and Rabura can cast magic together with Akari during some situations in Jewel Land.

(Source: Wikipedia)